Candy Crush Saga publisher King’s share price has been taking a thumping since it announced its financial results last night.

The company reported revenues of $593.6m and a net profit of $165.4m for the second quarter of 2014, which sounds healthy enough: most mobile games companies would be more than happy with those numbers.

But those revenues were actually down on the first quarter’s $606.7m – the first time King has recorded such a fall since before Candy Crush mania took off in early 2013.

Its gross bookings – a measure used by social games companies for how much people are spending in their games – were also down, from $641.1m in the first quarter of this year to $611.1m in the second quarter.

Here’s the phrase – from King’s official results announcement – that summarises why Wall Street has been spooked enough to knock off close to a quarter of the value of the company, which went public earlier in the year:

“The decreases in both gross bookings and revenue from first quarter 2014 to second quarter 2014 were primarily due to lower gross bookings from Candy Crush Saga, which were only partially offset by increased gross bookings and revenue from Farm Heroes Saga and Bubble Witch 2 Saga following its launch on web and mobile in June 2014.”

Players are spending less money in King’s powerhouse puzzle game, and the newer Saga titles that have joined it on Apple and Google’s app stores aren’t yet making up for that decline. But will that change in the coming months? The worst nightmare for King is the recent history of one of its key rivals: Zynga.

I’ve been comparing the two companies’ financial results, and there’s a real risk for King that this summer could be its equivalent of Zynga’s summer of 2012: a peak in revenues and players, followed by a steady decline.

Could players fall out of love with “Saga” games as they did with “Ville” games two years ago? Here’s some of the data behind that comparison, with apologies for the tiny text labels – they’re not a barrier to understanding the trends. In each graph, King’s financials are the blue line, and Zynga’s the red.

What the numbers show

First, quarterly revenues for the two companies from the earliest point they were published in their respective IPO prospectuses: going back to the first quarter of 2010 for Zynga, and the first quarter of 2012 for King:

King’s revenues seem to have peaked in the third quarter of 2013, at the height of the Candy Crush craze. Zynga’s peaked in the first quarter of 2012, and the couple of quarters after each peak look strikingly similar on the graph.

How about bookings: that measure of how much people are actually spending on virtual items within each company’s games?

Turning my attention to player numbers, I chose to compare monthly unique users (MUUs in industry parlance) rather than monthly active users (MAUs), in an effort to understand how their overall number of players has risen and fallen – without players being counted twice if they play several games:

It’s also worth looking at the number of monthly unique payers (MUPs) – the number of people who’ve actually spent money within King and Zynga’s games, as opposed to simply playing them for free:

King’s high-point for monthly unique payers was actually last summer: the third quarter of 2013. Its MUPs have now fallen for three consecutive quarters, even if it’s only in the second quarter of this year that the company’s revenues declined.

What does this comparison suggest?

Here’s my theory: when Zynga’s business peaked in the summer of 2012 and then started to decline, one of the main causes was Ville-ennui.

People who’d been addicted to games like FarmVille and CityVille were tiring of the format: seeing new Ville games and deciding not to go down that long, clicky road again. The brand itself became a bit of a millstone, and Zynga wasn’t able to win those players back with newer games.

The big risk for King in 2014 is that “Saga” is the new “Ville”. Are more players who’ve sweet-swapped their way several hundred levels into Candy Crush Saga taking a look at new Saga games, with their familiar three-star level maps, and opting out?

It’s pure speculation: the financial data is supporting material for this hypothesis, but it certainly doesn’t prove it yet.

I do wonder, though, whether it’s a risk for any mobile game that becomes a craze – people may disappear down its digital rabbit hole for months, but when they resurface, the prospect of doing it again may not appeal.

And it’s at this point that a company like Zynga or King needs to come up with new ideas and brands that don’t feel like that same old rabbit hole.

Why might this theory be bunkum?

First, because there are some key differences between the two companies. One reason for Zynga’s decline was that its big success came on the web, on Facebook, just before the world and its aunt went mad for mobile games.

Zynga had some successes – Zynga Poker for example – but overall it struggled to adapt to a rapid shift in social gaming from web to mobile. Some of its high-profile moves to adapt – buying the developer of the Draw Something game just as that craze peaked – flopped dramatically.

King’s rise, on the other hand, was fuelled by exactly that shift from web to mobile: its revenues and audience took off like a rocket in the first quarter of 2013 as Candy Crush mania took hold on smartphones and tablets.

King had been around for years before that making web and Facebook games, but if it’s about to enter a tough period now, it’s not because of a platform transition.

A second difference between the two companies is their profitability. Since early 2012, Zynga has usually posted quarterly losses of tens of millions of dollars. By contrast, here are King’s quarterly profits since the start of 2013: $52.7m, $125.9m, $229.8m, $159.2m, $127.2m, $165.4m.

That should have helped the company build up a war chest for the next reason it might not be about to enter a Zynga-style decline: it can plough money into developing new non-Saga games, and it can scout about for acquisitions of companies that might bring it new hits.

The first signs of the latter came this week as part of King’s latest financial results: it’s buying a Singapore-based developed called Nonstop Games in a deal that could be worth up to $100m if certain targets are hit. The studio will be working on “new games outside of its traditional casual genre” to launch in 2015.

King’s stonking Candy Crush profits, together with its recent IPO, could be a base to snap up promising-looking developers and games as they emerge. Note Zynga’s recent upturn in some of the graphs above: partly fuelled by its acquisition of Clumsy Ninja developer NaturalMotion earlier this year.

Acquisitions could also address one of the biggest criticisms levelled at its Saga series: that it’s just rejigged versions of older games from other publishers like Bejeweled (Candy Crush Saga), Puzzle Bobble (Bubble Witch Saga) and Peggle (Papa Pear Saga).

It’s also worth noting that King is getting ready to release Candy Crush Soda Saga, which is an official sequel to the company’s biggest hit. The new game has been soft-launched in a few countries, with a global launch expected soon. Whether it can escape Saga-ennui is another question, though.

King isn’t guaranteed to be the next Zynga in terms of business decline, in other words. But its latest financial results are a stark reminder to its management and investors alike that it needs to learn the lessons from the FarmVille firm’s fall since its peak in the summer of 2012.

• Why is Candy Crush Saga so popular?